1. Field of the Invention
The present invention relates generally to the testing of integrated circuit packages, and more particularly, to a stackable test apparatus that supports the integrated circuit packages during loading, testing and unloading in a pressurized test chamber.
2. Description of the Related Art
Hermetically sealed electronic packages, such as integrated circuits, are ordinarily subject to leak testing to evaluate the effectiveness of the hermetic seal. Generally, to leak test the electronic package, it is placed in a pressurized atmosphere of a test gas, such as helium, for a period of time to force the test gas into the hermetic container through any cracks or imperfections. Helium is preferred as the test gas since it has an extremely small molecule compared to most leakage opening sizes. The testing procedures or techniques are often determined by industry standards. One such test standard is MIL-STD-883, METHOD 1014, SEAL, which is incorporated by this reference. The purpose of this test is to determine the effectiveness (hermeticity) of the seal of microelectronic and semiconductor devices with designed internal cavities.
The fine leak test is conducted by placing a number of electronic packages into a test or “bombing” chamber. The chamber is then sealed and receives highly pressurized helium gas. The electronic packages are “bombed” with pressurized helium for a period of time such that the helium enters the package through any small cracks or leaks. The electronic packages are removed from the chamber and tested in a mass spectrometer fixture. The spectrometer measures the amount of helium that escapes from the electronic packages in terms of a flow rate. If the flow rate exceeds a certain minimum, then the electronic package fails. The spectrometer chamber is filled with ambient air and is not pressurized.
Usually, to maximize the number of electronic packages that can be tested, the chamber is filled as full as possible. Unfortunately, maximizing the loading of the electronic packages into the chamber sometimes causes damage due to mishandling and stacking of the electronic packages in the bomb chamber. The electronic packages suffer damage to the lids, pins, leads, and other fragile elements. The damaged electronic packages are either be scrapped or repaired, costing unnecessary time and money.
It would be advantageous to develop an apparatus that would reduce damage to the electronic packages while loading and unloading the electronic packages in a test chamber for testing.
It would be advantageous if the developed apparatus also would protect the electronic packages during testing in the test chamber. It also would be advantageous if the apparatus would protect the electronic packages during transportation to and from the test chamber.
It would also be advantageous if the developed apparatus does not interfere with the testing of the electronic packages or the test procedure.